International Journal of Molecular Sciences Review Erythropoietin and Its Angiogenic Activity Patrícia Kimáková 1,†, Peter Solár 1,*,† ID , Zuzana Solárová 2, Radovan Komel 3 and Nataša Debeljak 3 ID 1 Laboratory of Cell Biology, Institute of Biology and Ecology, Faculty of Science, Pavol Jozef Šafárik University in Košice, Košice 04001, Slovak;
[email protected] 2 Institute of Pharmacology, Faculty of Medicine, P.J. Šafárik University in Košice, Košice 04001, Slovak;
[email protected] 3 Medical Centre for Molecular Biology, Institute of Biochemistry, Faculty of Medicine, University of Ljubljana, Ljubljana SI-1000, Slovenia;
[email protected] (R.K.);
[email protected] (N.D.) * Correspondence:
[email protected]; Tel.: +421-55-234-1199, Fax: +421-55-622-2124 † These authors contributed equally to this work. Received: 26 May 2017; Accepted: 11 July 2017; Published: 13 July 2017 Abstract: Erythropoietin (EPO) is the main hematopoietic hormone acting on progenitor red blood cells via stimulation of cell growth, differentiation, and anti-apoptosis. However, its receptor (EPOR) is also expressed in various non-hematopoietic tissues, including endothelium. EPO is a pleiotropic growth factor that exhibits growth stimulation and cell/tissue protection on numerous cells and tissues. In this article we review the angiogenesis potential of EPO on endothelial cells in heart, brain, and leg ischemia, as well as its role in retinopathy protection and tumor promotion. Furthermore, the effect of EPO on bone marrow and adipose tissue is also discussed. Keywords: erythropoietin; erythropoietin receptor; endothelial; angiogenesis; cancer 1. Introduction Erythropoietin (EPO) is the main hematopoietic cytokine that regulates the formation of red blood cells in the process of hematopoiesis [1].